Hvac fitting apparatus and method for use therewith

ABSTRACT

Disclosed is a fitting. The fitting comprises a base and a cover. The base is adapted to be and secured in use to a subfloor, prior to placement of a finished floor, to frame the roughed-in duct opening. The cover is connected to the base and adapted to impede infiltration of debris into the mechanical duct during construction. The base and the cover are connected such that the cover can be relatively easily removed from the base after the finished floor has been laid.

FIELD OF THE INVENTION

The invention relates to the construction industry.

BACKGROUND OF THE INVENTION

When constructing residential homes in North America, forced air heating and cooling systems are commonly employed. These systems typically include ductwork that receives conditioned air from a furnace or the like and delivers same to floor registers. More specifically, typical ductwork extends to a boot that is mounted to the underside of the subfloor and communicates with a roughed-in mechanical duct opening. After a finished floor has been applied over the subfloor, again leaving space corresponding with the roughed-in duct opening, a floor grate is applied. The floor grate overlaps the finished floor and creates a finished appearance. This arrangement is relatively economical and relatively aesthetically pleasing. However, as there is often a substantial period of time between the installation of the boot and the application of the floor grate, it is commonplace for debris to find its way into the ductwork during the construction process; removal of this adds substantial cost and inconvenience. It is known for wood patches to be temporarily nailed over the roughed-in openings, to avoid construction debris infiltration, but this incapacitates the HVAC system, which can be undesirable.

SUMMARY OF THE INVENTION

Forming one aspect of the invention is apparatus for use with a subfloor assembly, a finished floor and a floor grate. The subfloor assembly is defined by a mechanical duct and by a subfloor having a roughed-in mechanical duct opening communicating with the mechanical duct. The finished floor, in use, is disposed upon the subfloor and defines an aperture communicating and at least substantially in register with the roughed-in mechanical duct opening. The floor grate is of the type including a grating part and a tubular coupler. The grating part has a screened vent opening and is adapted such that, when operatively placed in use onto a finished floor, the grating part overlaps the finished floor on all sides of the aperture and the vent opening is aligned with and in register with the mechanical duct. The tubular coupler part is adapted, when the grating part is operatively positioned on a finished floor, to occupy the aperture and engage the finished floor to limit lateral movement of the floor grate relative to the finished floor.

The apparatus comprises a base member and a cover.

The base member is adapted to be permanently secured to said subfloor, prior to placement of said finished floor, to frame the roughed-in mechanical duct opening.

The cover is connected to the base member and adapted to impede infiltration of construction debris into the mechanical duct. The base member and the cover are connected in a manner such that the cover can be relatively easily removed from the base member at least after the finished floor has been laid.

According to another aspect of the invention, the cover can be frangibly connected to the base member.

According to another aspect of the invention, the apparatus can further comprise a rectangular tube which, in use, extends upwardly from the base member and is surrounded by the finished flooring.

According to another aspect of the invention, the length of the rectangular tube can be the thickness of the finished floor.

According to another aspect of the invention, the base member can be a nailing flange.

According to another aspect of the invention, the cover can have a vent passage defined therethrough.

According to another aspect of the invention, the apparatus can further comprise an air filter adapted to filter air passing through the vent passage.

According to another aspect of the invention, the filter and the cover can be adapted for snap-fit engagement with one another.

According to another aspect of the invention, the apparatus can further comprise an extender which, in use, receives the rectangular tube in close-fitting relation, defines an extension of the mechanical duct and is engaged by the coupler part of said grate to resist lateral movement of the floor grate relative to the finished floor.

According to another aspect of the invention, the extender and the rectangular tube can be adapted to permit telescopic motion of the rectangular tube into the extender and can be provided with portions that mechanically engage with one another to permit the height of the extension relative to the subfloor to be adjusted in use.

According to another aspect of the invention the interior dimensions of the rectangular tube can be selected from 3″×10″ and 4″×10″.

According to another aspect of the invention, the length of the rectangular tube can be selected from ⅜″ and ⅝″.

Forming yet another aspect of the invention is a system for use with a subfloor assembly, a finished floor and a floor grate. The subfloor assembly is defined by a mechanical duct and by a subfloor having a roughed-in mechanical duct opening communicating with the mechanical duct. The finished floor, in use, is disposed upon the subfloor and defines an aperture communicating and at least substantially in register with the roughed-in mechanical duct opening. The floor grate is of the type including a grating part and a tubular coupler part. The grating part has a screened vent opening and is adapted such that, when operatively placed in use onto a finished floor, the grating part overlaps the finished floor on all sides of the aperture and the vent opening is aligned with and in register with the mechanical duct. The tubular coupler part is adapted, when the grating part is operatively positioned on a finished floor, to occupy the aperture and engage the finished floor to limit lateral movement of the floor grate relative to the finished floor.

The system comprises fittings and extenders.

Each fitting includes a base member and a cover.

The base member is adapted to be permanently secured to the subfloor prior to placement of the finished floor to frame the roughed-in mechanical duct opening.

The cover is connected to the base member and adapted to impede infiltration of construction debris into the roughed-in mechanical duct opening.

The base member and the cover are connected in a manner such that the cover can be relatively easily removed from the base member at least after the finished floor has been laid.

Each extender, in use, engages a respective fitting, defines an extension of the mechanical duct and is engaged by the coupler part of said floor grate to resist lateral movement of the floor grate relative to the finished floor.

According to another aspect of the invention, the cover can be frangibly attached to the base member.

According to another aspect of the invention, the cover can have a vent passage defined therethrough.

According to another aspect of the invention, the system can further comprise air filters, each filter adapted to filter air passing through the vent passage.

According to another aspect of the invention, the fitting can further comprise a rectangular tube which, in use, extends upwardly from the base member.

According to another aspect of the invention, the extender and rectangular tube can be adapted to permit telescopic motion of the tube into the extender and can be provided with portions that mechanically engage with one another to permit the height of the duct extension relative to the subfloor to be adjusted in use.

According to another aspect of the invention, the fitting can comprising a pair of rectangular tubes, one of said pair, in use, extending upwardly from the base member and being surrounded by the finished flooring, the other of said pair, in use, extending downwardly from the base member and being surrounded by the subfloor.

The present invention provides a relatively low cost system that avoids infiltration of debris into the mechanical duct. Other advantages, features and characteristics of the present invention, as well as methods of operation and functions of the related elements of the structure, and the combination of parts and economies of manufacture, will become more apparent upon consideration of the following detailed description and the appended claims with reference to the accompanying drawings, the latter being briefly described hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a prior art floor grate in use on a finished floor;

FIG. 2 is a top plan view of the structure of FIG. 1;

FIG. 3 is a view along 3-3 of FIG. 2;

FIG. 4 is a view of a system according to an exemplary embodiment of the present invention;

FIG. 5 is a view of a portion of the structure of FIG. 4 in isolation;

FIG. 6 is a view of a portion of the structure of FIG. 3 in use on a subfloor assembly;

FIG. 7 is a view of the structure of FIG. 6 with a finished floor applied;

FIG. 8 is a view of the structure of FIG. 7 with the cover and filter removed and a prior art floor grate installed;

FIG. 9 is a view of a portion of the structure of FIG. 3 in use with a polished concrete floor and a conventional floor grate;

FIG. 10 is a view similar to FIG. 9 but showing a heated laminate floor;

FIG. 11 is a view similar to FIG. 5 showing an alternate embodiment;

FIG. 12 is a view similar to FIG. 5 showing another embodiment;

FIG. 13 is a view similar to FIG. 5 showing another embodiment;

FIG. 14 is a view showing a yet further alternate embodiment of the structure of FIG. 5; and

FIG. 15 is a view similar to FIG. 14 showing another embodiment.

FIG. 16A is a view showing the components of another exemplary system that embodies the invention;

FIG. 16B is a view of the structures of FIG. 16A, from the opposite side;

FIG. 17 is a view of the structure of encircled area 17 of FIG. 16A nailed to a subfloor;

FIG. 18A is a view of the structure of encircled area 18 of FIG. 16B in use with the structure of FIG. 17;

FIG. 18B is a view of the structure of FIG. 18A in use with the structure of encircled area 18B of FIG. 16A, the view being of the underside;

FIG. 19 is a view of the structure of FIG. 18A, to which a finished tile floor has been applied;

FIG. 20 is a view of the structure of FIG. 19, with the structures of encircled areas 18 and 18B removed and the finished floor shown in phantom, in use with the structure of encircled area 20 of FIG. 16A;

FIG. 21 is a top view of the structure of FIG. 20;

FIG. 22 is a view of the structure of FIG. 21 in use with the structure of encircled area 22 of FIG. 16A, the view being taken along section 22-22 of FIG. 21;

FIG. 23 is a view of the structure of FIG. 21 in use with a conventional floor grate;

FIG. 24 is a view of the structure of encircled area 24 of FIG. 16A in use with the structure of FIG. 18A; and

FIG. 25 is a view of the structure of FIG. 24 in use in a pour-in-place floor stem, the structure of encircled area 25 of FIG. 16A having been removed along with the structure of encircled area 18 of FIG. 16A.

DETAILED DESCRIPTION

As an initial matter, the present invention will be understood to be useful in association with a subfloor assembly, a finished floor 102 and a floor grate 104, of the type that is commonly found at least in North America and is shown in use and by way of example only in FIGS. 1-3.

The subfloor assembly shown is defined by: (i) a mechanical duct 106 defined by a boot 108 and; (ii) a plywood subfloor 110 having a roughed-in mechanical duct opening 112 communicating with the mechanical duct 106.

The finished floor 102 shown in FIGS. 1-3 is a hardwood product disposed upon and nailed to the subfloor 110 and defining an aperture 114 communicating and at least substantially in register with the roughed-in mechanical duct opening 112.

The grate 104 shown in FIGS. 1-3 is of the type including a grating part 116 and a tubular coupler part 118. The grating part 116 has a screened vent opening 120 and is placed onto the finished floor 102 such that the grating part 116 overlaps the finished floor 102 on all sides of the aperture 114 and the vent opening 120 is aligned with and in register with the mechanical duct 106. The coupler part 118 occupies aperture 114 and engages the finished floor 102 to limit lateral movement of the floor grate 104 relative to the finished floor 102.

Turning now to the components of the present invention, a system 20 according to an exemplary embodiment of the present invention is illustrated in FIG. 4 and will be seen include a fitting 22, a filter 24 and an extender 26.

Fitting 22 is shown in FIG. 5 and includes a cover 28, a base member 30 and a rectangular tube 32. Cover 28 includes a rectangular panel 34 having a vent passage 36 extending therethrough and an annular boss 38 extending from the panel 34 in surrounding relation to the vent passage 36. The base member 30 is a rectangular flange having nailing holes 40, framing the panel 34 and frangibly connected thereto by a plurality of tabs 42. Rectangular tube 32 has a plurality of ribs 44 extending therearound, extends from the base member 30 and also frames the panel 34.

The filter 24 is adapter for snap-fit engagement with the cover 28, specifically, with the annular boss 38, and when engaged, filters air passing through the vent passage 36.

The fitting 22 and filter 24 are shown in use in FIG. 6. Herein, it will be seen that the base member 30 can be permanently secured to the subfloor 110 prior to placement of the finished floor (not shown), to frame the roughed-in mechanical duct opening 112. So placed:

-   -   the panel 34 impedes infiltration of construction debris into         the roughed-in mechanical duct opening 112 during the         construction process; and     -   the rectangular tube 32 provides a convenient guide for the         subsequent installation of the finished floor, i.e. the         installer can ensure a good fit of the finished floor by causing         the rectangular tube 32 to be surrounded by the finished         flooring in close-fitting relation

FIG. 7 shows the structure of FIG. 6 in use with a finished floor 102. Herein, it will be seen that the rectangular tube 32 is the length of the thickness of the finished floor 102, thereby to substantially conceal the finished floor 102 and add to the overall aesthetic.

Once construction is complete, the cover and filter can be removed, and a conventional floor grate 104 installed, as shown in FIG. 8. The frangible connection provides by the tabs 42 (shown in FIG. 6) renders this step relatively easily done, without tools. It will be evident in FIG. 8 that the rectangular tube 32 is engaged by the coupler part 118 of the floor grate 104 to resist lateral movement of the floor grate 104 relative to the finished floor 102, i.e. locking the grate 104 in position.

Turning now to the extenders 26, same are employed for pour-in-place flooring and will be seen in FIG. 4 to have:

-   -   a rectangular shape similar to, but slightly larger than, the         rectangular tube of the fitting, thereby to permit telescopic         motion of the rectangular tube 32 into the extender 26; and     -   a plurality of rib portions 46 formed on an interior thereof         that mechanically engage with the rib portions of the         rectangular tube to permit the height of the extension relative         to the subfloor to be adjusted in use.

FIG. 9 shows an extender 26 in use with a polished concrete finished floor 102; it will be seen that the extender 26 serves the function of a stay-in-place form while the pour-in-place flooring is curing and thereafter is engaged by the coupler part 118 of the floor grate 104 to resist lateral movement of the floor grate 104 relative to the finished floor 102.

FIG. 10 shows an extender 26 in use with a heated laminate finished floor 102B/102A; it will be seen that the extender 26 serves the function of a stay-in-place form while the liquid gypsum flooring 102A cures; then serves as a guide for the subsequent installation of the laminate 102B; and then finally is engaged by the coupler part 118 of the floor grate 104 to resist lateral movement of the floor grate 104 relative to the finished floor 102B/102A.

Although not marked on the drawings, it will be understood that in FIG. 5, the interior dimensions of the rectangular tube are 3″×10″ and the length of the rectangular tube is ⅜″, thereby adapting the system for use with any conventional 3″×10″ floor grate and ⅜″ flooring.

FIG. 11 is a view similar to FIG. 5, wherein the interior dimensions of the rectangular tube are 4″×10″ and the length of the rectangular tube is ⅜″ thereby adapting the system for use with any conventional 4″×10″ floor grate and ⅜″ flooring.

FIG. 12 is a view similar to FIG. 5, wherein the interior dimensions of the rectangular tube are 3″×10″ and the length of the rectangular tube is ⅝″ thereby adapting the system for use with any conventional 3″×10″ floor grate and ⅝″ flooring.

FIG. 13 is a view similar to FIG. 5, wherein the interior dimensions of the rectangular tube are 4″×10″ and the length of the rectangular tube is ⅝″ thereby adapting the system for use with any conventional 4″×10″ floor grate and ⅝″ flooring.

FIG. 14 shows another embodiment of the fitting, wherein the panel 34 and flange 30 parts are positioned at an intermediate position, to bisect lengthwise the rectangular tube and the annular boss 38. Although not marked on the drawings, it will be understood that in FIG. 14, the interior dimensions of the rectangular tube 32 are 3″×10″ and the length of the rectangular tube is 1″, with ⅜″ protruding from one side of the panel 34 and ⅝″ protruding from the other. This fitting is thus adapted for use with any conventional 3″×10″ floor grate and ⅜″ flooring or ⅝″, depending upon the orientation.

FIG. 15 shows an embodiment similar to FIG. 14 but wherein the interior dimensions of the rectangular tube are 4″×10″

As yet another embodiment, not shown, the rectangular tube and cover could be formed as part of an HVAC boot, with the base member omitted or adapted for engagement with the underside of the subfloor.

A yet further embodiment is shown in FIG. 16A-25.

FIG. 16A shows six components 202, 204, 206, 208, 210 and 212 which collectively define a system 200 sharing the major structural components of the system of FIGS. 1-15 but configured in a slightly different way.

The first component 202 includes base member 30 and a support flange 211. Support flange 211 has cut-outs 214, locking tabs 216, locking sockets 218 and alignment feet 220. Base member 30 continues to have nailing holes 40.

The second component 204 is a cover 28 that includes a rectangular panel 34 having a vent passage 36 defined, in this case, by a plurality of vent subpassages 222 and additionally includes a plurality of lugs 224, a pair of slots 226, a pair of support bands 228 and a plurality of tabs 230.

The third component 206 includes an extender 26 and additionally includes a pair of stiffeners 232. The extender 26 has plugs 234.

The fourth component 208 is the construction filter 24. In this embodiment, the construction filter 24 is simply a rectangular sheet of filter media.

The fifth component 210 is a filter support having a plurality of ribs 236, a plurality of tabs 238, lugs 240 and slots 242.

The sixth component 212 is a residential filter including a cardboard frame 242 and a filter media insert 244.

The manner in which this system 200 can be used in shown in FIGS. 17-25.

Turning first to FIG. 17, this illustration shows the first component 202 secured to a subfloor 243 by nails 245.

FIG. 18A shows the structure of FIG. 17 with the second component 204 fitted therein such that the lugs 224 thereof are disposed in the cut-outs 214 and such that locking tabs 216 are engaged in slots 226; the engagement provided by the lugs 224 and locking tabs 216 provides for the second component 204 to be securely, releasably retained in position, thereby to avoid inadvertent dislodgement. This arrangement ensures that large construction debris is blocked against entry into the mechanical duct (not shown) by the screening provided by second component 204. It will also be evident that the locking tabs 216 provide for a snap-fit securement, which can add to consumer acceptance in some situations. It will be understood that the second component 204 is strong enough to bear the weight, for example, of a person, reducing the likelihood of injury associated with breakage.

The vent passage 36 will be seen to be defined by a plurality of ribs that provide a contoured upper surface; the contour lessens the likelihood of, for example, boxes or wood being stacked upon the structure in use, thereby increasing the likelihood that HVAC will function during construction.

FIG. 18B shows the underside of the structure of FIG. 18A, with the construction filter 24 disposed upon the rectangular panel 34 and held in place by the support bands 228 and tabs 230. It will be evident that this arrangement corresponds to the arrangement of FIG. 6, i.e. in this arrangement, even fines are blocked against entry in the mechanical duct, via the construction filter 24.

FIG. 19 shows the structure of FIG. 18A, with a finished floor 250 installed. It will be evident that this arrangement corresponds to the structure of FIG. 7, with the support flange 211 defining the outer surface of the rectangular tube 32.

FIG. 20 shows the structure of FIG. 19, with the second 204 and fourth 208 components removed and the filter support 210 installed. Herein, it will be seen that filter support 210 fits in nested relation inside the rectangular tube 32 and is suspended by its lugs 240 which engage the cut-outs 214. Locking tabs 216 will also be seen to be engaged in slots 242; locking tabs 216 again provide for a snap-fit securement, which can add to consumer acceptance in some situations.

FIG. 22 is a view along 22-22 of FIG. 21, but also showing the position of the residential filter 212 in use; herein, it will be seen that the residential filter 212 is retained in a slot defined by the ribs 236 and the tabs 238.

FIG. 23 shows a conventional floor grate 248 inserted interiorly of the filter support (not shown). It will be evident that this arrangement corresponds to the structure of FIG. 1, with the interior surface of the filter support 210 defining the interior surface of the rectangular tube 32.

FIG. 24 shows the third component 206 in use with structure of FIG. 18A. Herein, it will be evident that the support flange (not visible) is received in nested relation within the third component 206, such that the extender 26 may serve as a form for pour-in-place flooring, as mentioned with reference to FIGS. 9 and 10.

Notably, plugs 234 of third component 206 engage locking sockets 218 in snap-fit relation, so as to securely hold third component 206 in place until the pour-in-place flooring has cured.

Once the concrete or other pour-in-place flooring has cured, the stiffeners 232 can be removed, with a reciprocating saw or the like, as shown in FIG. 25, and the filter support 210 and residential filter 212 can be installed in the manner described with reference to FIGS. 21 and 22, as shown in FIG. 25.

Whereas certain embodiments are herein illustrated and described, it will be appreciated that further variations are possible.

For example, whereas a nailing flange is shown in both illustrated embodiments, it should be understood that the flange could be secured by adhesive or the like.

As well, whereas the flange, cover, tube and extender are all illustrated as rectangular, this is only advantageous, to permit use of the system with conventional rectangular floor grates.

Further, whereas the illustrated rectangular tube is generally solid, this is only advantageous, to permit use as part of a stay-in-place form; where this is not required, the tube could be defined, for example, by a plurality of tabs spaced apart from one another around a rectangular perimeter.

Accordingly, it should be understood that the invention is to be limited only by the accompanying claims, purposively construed. 

1. Apparatus for use with a subfloor assembly, a finished floor and a floor grate, the subfloor assembly being defined by a mechanical duct and by a subfloor having a roughed-in mechanical duct opening communicating with the mechanical duct; the finished floor, in use, being disposed upon the subfloor and defining an aperture communicating and at least substantially in register with the roughed-in mechanical duct opening; and the floor grate being of the type including: (i) a grating part having a screened vent opening and adapted such that, when operatively placed in use onto a finished floor, the grating part overlaps the finished floor on all sides of the aperture and the vent opening is aligned with and in register with the mechanical duct; and (ii) a tubular coupler part adapted, when the grating part is operatively positioned on a finished floor, to occupy the aperture and engage the finished floor to resist lateral movement of the floor grate relative to the finished floor, the fitting comprising: a base member adapted to be permanently secured to the subfloor, prior to placement of the finished floor, to frame the roughed-in opening; and a cover connected to the base member and adapted to impede infiltration of construction debris into the mechanical duct, wherein the base member and the cover are connected in a manner such that the cover can be relatively easily removed from the base member at least after the finished floor has been laid.
 2. Apparatus according to claim 1, wherein the cover is frangibly connected to the base member or engages the cover in snap-fit relation.
 3. Apparatus according to claim 1, further comprising a rectangular tube which, in use, extends upwardly from the base member and is surrounded by the finished flooring.
 4. Apparatus according to claim 3, wherein the length of the tube is the thickness of the finished floor.
 5. Apparatus according to claim 1, wherein the base member is a nailing flange.
 6. Apparatus according to claim 1, wherein the cover has a vent passage defined therethrough.
 7. Apparatus according to claim 6, further comprising an air filter adapted to filter air passing through the vent passage.
 8. Apparatus according to claim 7, wherein the filter and the cover are releasably engaged with one another in use.
 9. Apparatus according to claim 3 and further comprising an extender which, in use, receives the rectangular tube in close-fitting relation, defines an extension of the duct and is engaged by the coupler part of said grate to resist lateral movement of the floor grate relative to the finished floor.
 10. Apparatus according to claim 9, wherein the extender and the rectangular tube are adapted to permit telescopic motion of the rectangular tube into the extender and are provided with portions that mechanically engage with one another to permit the height of the extension relative to the subfloor to be adjusted in use.
 11. Apparatus according to claim 3, wherein the interior dimensions of the rectangular tube are 3″×10″ or 4″×10″ and the length of the rectangular tube is ⅜″ or ⅝″.
 12. Apparatus according to claim 3, further comprising a filter and wherein the base member includes a nailing flange and a support flange; a filter support is releasably coupled to the base member; the rectangular tube is defined by the support flange and the filter support; and the filter is releasably engaged to the filter support and, in use, filters the air passing from the mechanical duct through the floor grate.
 13. A system for use with a subfloor assembly, a finished floor and a floor grate, the subfloor assembly being defined by a mechanical duct and by a subfloor having a roughed-in mechanical duct opening communicating with the mechanical duct; the finished floor, in use, being disposed upon the subfloor and defining an aperture communicating and at least substantially in register with the roughed-in mechanical duct opening; and the floor grate being of the type including: (i) a grating part having a screened vent opening and adapted such that, when operatively placed in use onto a finished floor, the grating part overlaps the finished floor on all sides of the aperture and the vent opening is aligned with and in register with the mechanical duct; and (ii) a tubular coupler part adapted, when the grating part is operatively positioned on a finished floor, to occupy the aperture and engage the finished floor to resist lateral movement of the floor grate relative to the finished floor, the system comprising fittings, each fitting including a base member adapted to be permanently secured to the subfloor prior to placement of the finished floor to frame the roughed-in mechanical duct opening; and a cover connected to the base member and adapted to impede infiltration of construction debris into the roughed-in mechanical duct opening, wherein the base member and cover are connected in a manner such that the cover can be relatively easily removed from the base member at least after the finished floor has been laid; and one or more of: extenders, each extender, in use, engaging a respective fitting, defining an extension of the mechanical duct and being engaged by the coupler part of said floor grate to resist lateral movement of the floor grate relative to the finished floor; and filters, each filter, in use, being releasably operatively engaged to the fitting and filtering the air passing from the mechanical duct through the floor grate.
 14. A system according to claim 13, wherein the cover is frangibly attached to the base member or engaged the base member in snap-fit relation.
 15. A system according to claim 13, wherein the cover has a vent passage defined therethrough.
 16. A system according to claim 13, wherein the fitting further comprises a rectangular tube which, in use, extends upwardly from the base member.
 17. A system according to claim 16, wherein the extender and rectangular tube are adapted to permit telescopic motion of the tube into the extender and are provided with portions that mechanically engage with one another to permit the height of the duct extension relative to the subfloor to be adjusted in use.
 18. Apparatus according to claim 3, further comprising a pair of rectangular tubes, one of said pair, in use, extending upwardly from the base member and being surrounded by the finished flooring, the other of said pair, in use, extending downwardly from the base member and being surrounded by the subfloor.
 19. A system according to claim 13, wherein the covers are releasably connected to the base member; and further comprising: filter supports, each filter support, in use, being releasably connected to a base member, occupied by a conventional floor grate and releasably connected to and operatively supporting one of the filters. 